I sail the middle and upper Chesapeake a lot. I have an AT&T phone. My partner has a Verizon phone. We find very little difference between the two services from Chesapeake City to the Virginia border.

Last week I sailed up the Bay finishing an offshoredelivery with AT&T, Verizon, and Sprint phones on board. Sprint was very problematic until we got North of the Patuxent River. Both Verizon and AT&T had dead spots in mid Bay. I believe the carriers are doing a better job (from their perspective) at tuning coverage areas for each tower and open water is not their priority. We definitely saw a difference between mid-Bay and closer to shore.

I have a verizon unlimited data plan. So I'm good there. We need a second phone for the boss. The straight talk android device is on the sprint network so that is the focus of the original question. The viability of sprint.
I can deal with poor signal when out on the water. We want to have decent service when at anchor or at the dock with this phone.

Straighttalk uses different networks for different phones. Some of their phones use sprint, some use att, and I think some even use verizon... You can buy an at&t phone (like an iphone) and just get an att compatible sim card from straighttalksim.com and still be on the att network with straighttalk pricing

For android on straight talk you get sprint.
Some of the other smart phones are att & some are verizon. If the model number ends in G, it's att.

We took a left turn...

My verizon droid 3 can act as a wifi hotspot.
Verizon is giving us 2gb for $20 on my existing account. I'm transmitting secure wifi to the i-pad for her surfing needs. It's a separate data stream from my droid data and they claim 30' range.
Then adding a straighttalk/att smartphone for calls, text, e-mails and minimal data at $30. So it looks like a good setup for &50/mo

For android on straight talk you get sprint.
Some of the other smart phones are att & some are verizon. If the model number ends in G, it's att.

We took a left turn...

My verizon droid 3 can act as a wifi hotspot.
Verizon is giving us 2gb for $20 on my existing account. I'm transmitting secure wifi to the i-pad for her surfing needs. It's a separate data stream from my droid data and they claim 30' range.
Then adding a straighttalk/att smartphone for calls, text, e-mails and minimal data at $30. So it looks like a good setup for &50/mo

I'm using this hotspot with my Droid Galaxy pad right now. I have locked up twice just trying to post this. I nearly always have 4 bars, but it seems the poor service is not related to the reception at all. Often it will be quick for 5 mins or so and then slow down incredibly. They must be buffering or something. I cant wait for my contract to run out. If you see a lot of mis spelled words in my posts (which you do!) it's because it's too much trouble to try to edit them out. Maybe it's better in another part of the country, but my phone service is fine... the data link is terrible...except on an occassional good day..

__________________"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard